1. Field of the Invention
The present invention relates to a method and apparatus for converting a slitter into a four high cold reduction mill.
2. Description of the Prior Art
In general arbor slitters and multi-roll cold reduction machines are known to those of ordinary skill in the art. A useful description of slitting equipment can be found in the book entitled "COIL SLITTING" by John W. Rogers and William H. Millan published in 1972 by the Corinthian Press, Cleveland, Ohio. Similarly, an exhaustive description of various types of multi-roll mills can be found in the book entitled "COLD ROLLING OF STEEL" by William L. Roberts published in 1978 by Marcel Decker, Inc. of New York City. Various other descriptions of the methods and apparatuses used for the splitting and milling of steel are also available to the general public.
Many industries, such as the automobile industry, use substantial quantities of cold rolled steel. Unfortunately, the energy consumed in producing cold rolled steel is high because it takes a lot of work to cold reduce steel from one dimension to another. Accordingly, the cost of cold rolled steel is relatively high. In the last few years that cost has increased substantially going from approximately 8 cents a pound in 1972 to about 25 cents a pound in 1984. Therefore, there is a need to find ways to minimize the cost of producing cold rolled steel. There are certain markets where expensive cold rolled steel could be replaced with less expensive hot rolled steel. For example, in the automobile industry it would be possible to replace cold rolled steel in certain non-exposed areas where surface finish and bends are not important, but where tolerance is.
Part of the cost of producing cold rolled steel is a result of the cost of the equipment itself. A typical steel converting operation would include separate slitting and cold reduction equipment. The cost of the additional cold reduction equipment can be prohibitive for a small steel converting operation. The cost factor becomes even more critical in the context of competition from foreign imports. Accordingly, a means was sought to reduce the cost of producing cold rolled steel, especially steels where relatively small amounts of reduction were required.
There are a few references in the patent literature of possible relevance to the issue of converting one metal working device into another. For example, U.S. Pat. No. 3,875,655 entitled "Convertible Metal Working Machine" generally discusses a means for converting a movable shear machine into a device for performing other metal working operations. U.S. Pat. No. 4,187,710 discloses a method for rolling and slitting simultaneously though it does not appear to address the question of converting a slitter apparatus into a rolling mill.
U.S. Pat. No. 3,566,515 is of general interest in that it discloses a roll grinding machine having a structure of possible relevance which includes a detachable feature. A number of prior art references, too numerous to list, discuss various techniques for removing housings and/or bearings for the purpose of replacing work rollers with fresh rollers.
Also, U.S. Pat. No. 1,561,803 is of general interest in that it discloses a strip straightening attachment for having a structure of possible relevance for using with rotary shears.
Insofar as understood, none of the prior art references known to the inventor either taken individually, or in combination, suggest the novel method and apparatus disclosed herein for converting an arbor slitter into a four high cold rolled mill.